The invention refers to a method for reeling a ribbon-like or filamentary material fed to a bobbin winder and wound up in cross winding with precision winding in which the integrals of the angular rotation of the bobbin are recorded as impulses by a first sensor and the integrals of the angular rotation of the drive for the traversing thread guide are recorded as impulses by a second sensor, the sums of the integrals of the angular rotation are compared with each other and the drive for the traversing thread guide is regulated depending on this. At the same time, the invention also comprises a bobbin winder for executing the method. The filamentary material which is to be wound is understood to include, in particular, threads and yarns or ribbons.
A method of the aforementioned type is known from U.S. Pat. No. 4,093,146 to Haley. Here, specific sensors supplying impulses are employed. A transmission is provided between the bobbin drive and the pulse generator, and this determines the bobbin ratio. The impulses registered are used exclusively for triggering a stepping motor which drives the traversing thread guide. The use of a stepping motor serves for altering the width passed over by the traversing thread guide. As a consequence of using a transmission having gear wheels, the reeling method is encumbered with all the disadvantages which will be explained in detail.
A method and a bobbin winder are known from EP-PS 55,849 in which cross winding in staged precision winding is employed. A first speedometer, which detects the bobbin r.p.m. per unit of time and transmits this to a regulator, is allocated to the bobbin or the bobbin spindle respectively. The drive for the traversing thread guide is also equipped with a speedometer. The two values of the speedometers are compared and fed to a regulator which itself in turn influences the drive for the traversing thread guide. The use of speedometers has various disadvantages. They must be adjusted at regular chronological intervals, they are temperature-dependent when in use and the accuracy with which they maintain a specific bobbin ratio is not perfect. A speedometer is an analog instrument, the accuracy of which depends on its design and construction.
U.S. Pat. No. 4,667,889 to Gerhartz also demonstrates a method for winding up threads in cross winding with staged precision winding. In order to achieve optimum thread placement on the bobbin, the bobbin ratios must not only be calculated in advance with great accuracy, but they must also be adhered to. As there is a limit to the electrical and electronic measuring and regulating technology for determining the rotational speeds and maintaining the proportion between the drive for the bobbin spindle and the drive for the traversing thread guide, it is proposed that in order to improve the winding build-up, the bobbin ratio be modulated in each reeling phase. The modulation width should be less than 0.1%.